// 文章详情
<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar class="page-nav-bar" 
    left-arrow title="黑马头条"
    @click-left="$router.back()"></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div v-if="loading" class="loading-wrap">
        <van-loading color="#3296fa" vertical>加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div v-else-if="article.title" class="article-detail">
        <!-- 文章标题 -->
        <h1 class="article-title">{{ article.title }}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo"
          />
          <div slot="title" class="user-name">{{ article.aut_name }}</div>
          <div slot="label" class="publish-date">
            {{ article.pubdate | relativeTime }}
          </div>

          <!-- <van-button
             v-if="article.is_followed"
            class="follow-btn"
            round
            size="small"
            :loading='followLoading'
            @click="onFollow"
          >已关注</van-button>

          <van-button
            v-else
            class="follow-btn"
            type="info"
            color="#3296fa"
            round
            size="small"
            icon="plus"
             :loading='followLoading'
            @click="onFollow"
            >关注</van-button
          > -->
          <!--
            模板中的 $event 是事件参数
            当我们传递给子组件的数据既要使用还要修改。
              传递：props
                :is-followed="article.is_followed"
              修改：自定义事件
                @update-is_followed="article.is_followed = $event"
            简写方式：在组件上使用 v-model
              value="article.is_followed"
              @input="article.is_followed = $event"

            如果需要修改 v-model 的规则名称，可以通过子组件的 model 属性来配置修改

            一个组件上只能使用一次 v-model，
            如果有多个数据需要实现类似于 v-model 的效果，咋办？
            可以使用属性的 .sync 修饰符。
           -->
          <!-- 关注作者子组件 -->
          <FollowUser
            :is-followed="article.is_followed"
            v-model="article.is_followed"
            :user-id="article.aut_id"
          />
        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div
          class="article-content markdown-body"
          v-html="article.content"
          ref="article-content"
        ></div>
        <van-divider>正文结束</van-divider>
        <!-- 文章评论列表 -->
        <CommentList
          @onload-success="totalCommentCount = $event.total_count"
          :source="article.art_id"
          :list="commentList"
          @reply-click="onReplyClick"
        />
        <!-- /文章评论列表 -->
        <!-- 底部区域 -->
        <div class="article-bottom">
          <van-button class="comment-btn" type="default" round size="small"
            @click="isPostShow= true">写评论</van-button
          >
          <van-icon name="comment-o" :info="totalCommentCount" color="#777" />
          <!-- <van-icon color="#777" name="star-o" /> -->
          <!-- 收藏子组件 -->
          <CollectArticle
            class="btn-item"
            v-model="article.is_collected"
            :article-id="article.art_id"
          />
          <!-- 点赞子组件 -->
          <LikeArticle
            class="btn-item"
            v-model="article.attitude"
            :article-id="article.art_id"
          />

          <van-icon name="share" color="#777777"></van-icon>
        </div>
        <!-- /底部区域 -->
        <!-- 发布评论弹出层 -->
        <van-popup v-model="isPostShow"
        position="bottom">
        <CommentPost
        @post-success='onPostSuccess'
        :target = 'article.art_id'
        />
        </van-popup>
        
        <!-- 发布评论弹出层 -->
      </div>

      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div v-else-if="errStatus == 404" class="error-wrap">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div v-else class="error-wrap">
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button class="retry-btn" @click="loadArticle">点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>
    <!-- 回复评论 -->

    <!-- 弹出层是懒渲染，只有第一次会渲染里面的内容，其余的只会控制弹出框的显示与隐藏 -->
    <van-popup v-model="isReplyShow" position="bottom" style="height:100%">
      <!-- v-if条件渲染
      true渲染
      false销毁
       -->
       <CommentReply 
       v-if="isReplyShow"
       :comment = 'currentComment'
       @click-close='isReplyShow=false'
       />
    </van-popup>
    <!-- /回复评论 -->
  </div>
</template>

<script>
import { getArticleById } from "@/api/article";
import { ImagePreview } from "vant";
import FollowUser from "@/components/follow-user";
import CollectArticle from "@/components/collect-article";
import LikeArticle from "@/components/like-article";
import CommentList from "./components/comment-list.vue";
import CommentPost from './components/comment-post.vue'
import CommentReply from './components/comment-reply.vue'
// ImagePreview({
//   images: [
//     'https://cdn.jsdelivr.net/npm/@vant/assets/apple-1.jpeg',
//     'https://cdn.jsdelivr.net/npm/@vant/assets/apple-2.jpeg',
//   ],
//   // 起始位置
//   startPosition: 0,
//   onClose(){
//     console.log('onClose');
//   }
// });
export default {
  name: "ArticleIndex",
  components: { FollowUser, 
  CollectArticle, 
  LikeArticle, 
  CommentList ,
  CommentPost,
  CommentReply},
  // 给所有的后代组件提供数据
  provide:function(){
    return{
     articleId:this.articleId
    }
  },
  props: {
    articleId: {
      type: [Number, String, Object],
      required: true,
    },
  },
  data() {
      return {
      article: {}, //文章详情
      loading: true, //加载状态
      errStatus: 0, //失败状态码
      followLoading: false,
      totalCommentCount: 0,
      isPostShow:false,//控制发布评论的状态
      commentList:[],//评论列表
      isReplyShow:false, //回复评论弹出框
      currentComment:{},//当前点击回复的评论项
    };
  },

  created() {
    this.loadArticle();
  },
  methods: {
    async loadArticle() {
      this.loading = true;
      try {
        const { data } = await getArticleById(this.articleId);
        //  数据驱动视图不是立即的
        this.article = data.data;

        setTimeout(() => {
          this.previewImage();
        }, 0);

        // 初始化图片点击预览
        this.$refs["article.content"];
        // if (Math.random() > 0.5) {
        //   JSON.parse('dsankljdnskaljndlkjsa')
        // }
      } catch (error) {
        if (err.response && err.response.status == 404) {
          this.errStatus = 404;
        }
        // this.$toast('获取详情失败')
      }
      // 无论成功失败都要关闭loading
      this.loading = false;
    },
    previewImage() {
      const articleContent = this.$refs["article-content"];
      const imgs = articleContent.querySelectorAll("img");
      // 获取所有img地址
      const images = [];

      imgs.forEach((img, index) => {
        images.push(img.src);
        // 给每个img注册点击事件，调用预览方法
        img.onclick = () => {
          ImagePreview({
            // 预览的图片地址
            images,
            // 起始位置 从0开始
            startPosition: index,
          });
        };
      });
    },
    // 发布评论子组件的自定义事件
    onPostSuccess(data){
       // 关闭弹出层
       this.isPostShow = false
            // 将发布的内容放到顶部
        this.commentList.unshift(data.new_obj)
    },
    onReplyClick(comment){
      this.currentComment = comment
      // 显示评论回复弹出层
      this.isReplyShow = true
    }
  },
};
</script>

<style scoped lang="less">
@import "./github-markdown.css";
.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    /deep/.van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>